The invention concerns a disc-like plastic body with inlay portion according to the introductory part of patent claim 1. Fields of application of the present subject of invention are for example casino chips, parking tokens, shopping tokens, value tokens, amusement arcade tokens, personalisation tokens, for example as a pass card.
A disc-like plastic body of this kind has for example become known with the subject of EP 444 373 A1. With this known plastic body the inlay portion is inserted in a central recess of an annular plastic body, the inlay portion being pressed into an inner peripheral annular groove of the plastic body and held there. With this technique there is the drawback that there is merely a bonding connection (form-locking connection) between the outer annular portion and the inner filler body (inlay portion), this latching connection not necessarily withstanding high stresses.
Another drawback is that on the plastic body there are of course edge markings in the form of lugs, which however extend upwards from one side only. If therefore it is a question of providing edge markings on such a plastic body, EP 444 373 A1 provides that on the annular outer portion there are attachments which point upwards in an axial direction and which laterally overlap the edge. However, high production costs are associated with this, because in general these attachments have to be formed integrally on the outer peripheral edge, which is associated with high tooling costs.
Moreover high finishing costs are incurred because the attachments cannot be formed integrally on the annular portion in such a way that they fit immediately; appropriate grinding work is necessary to make the attachments e.g. flush with the top surface and integrate them in the top surface.
It is therefore the object of the invention to develop a plastic body of the kind mentioned hereinbefore in such a way that its appearance is more pleasing and furthermore it is to be substantially easier and cheaper to make.
To achieve the stated object, the invention is characterised by the technical instruction of claim 1.
The invention essentially consists in that, starting from a filler body which holds the inlay portion inside it, this filler body is encompassed by two lid-like films, one film after the fashion of a cup surrounding the filler body on one side and the other, opposite film after the fashion of a lid being applied to the opposite side of the filler body.
In this case the cup and/or the lid preferably comprise attachments in each case arranged radially at the outer circumference in a star shape, the cup hereinafter being referred to as a star cup and the lid as a star lid.
With the given technical instruction the result is therefore the essential advantage that the said portionsxe2x80x94star cup and star lidxe2x80x94are now formed integrally directly on the filler body in the plastic injection moulding process, with the result that the lateral attachments formed integrally on the star cup can extend around the outer edge lines of the filler body in the injection moulding process and form edge markings.
The edge markings are accordingly formed by the radial, outwardly directed attachments of the upper and/or lower star film and during the injection moulding process are pulled around the outer edges of the filler body and injection-moulded in one piece with the material of this filler body.
Hence there is an absolutely reliable bond between the radially outer attachments and the edges of the filler body, and no finishing of a plastic body made in this way is necessary.
In EP 444 373 B1, as mentioned, finishing had to be done because the radial attachments which form the edge markings had to be inserted and not attached by injection moulding. Only a latching connection which was not injection-moulded was therefore involved, with the result that the durability and wear resistance of the plastic body suffered.
Another advantage of the present invention lies in that, by contrast with EP 444 373, the inner filler body is no longer held in a form-locking connection in a peripheral outer body, but only encompassed and enclosed from both sides (top surfaces) by the above-mentioned star cup film and the star lid film.
This encompassment and enclosure take place during the injection moulding process, i.e. the said films are attached by injection moulding to the filler body in the injection moulding process, with the result that there is a material locking bond and the materials of the film and filler body interlock and mesh with each other, which was unknown in the state of the art.
Hence there is an absolutely tight connection of the filler body to the upper and lower lid film bodies, integral with the material, which was previously unknown in the state of the art.
Because according to the invention on at least one of the lid films are arranged radial edge attachments which are bent round during injection moulding and attached to the peripheral edge of the filler body by injection moulding, the result is an edge of the plastic body made by this means that can be subjected to extremely high stresses, with the advantage that the edge markings which are formed by the attachments are highly wear-resistant, abrasion-resistant and capable of free graphic design, wherein they can be designed either in the colour of the lid films or in any other colour.
Due to the fact that the filler body extends over the whole surface of the plastic body (and is not located just in the centre region), a substantially greater volume and weight of the filler body are achieved. This is one of the essential requirements of amusement arcade tokens which must have a certain minimum weight. With the subject of the present invention this minimum weight can very easily be achieved, for the filler body extends practically over the whole outside diameter of the games token and is not just confined to a central region.
Because there is now a higher volume available for the filler body, there is also no need for expensive materials that make the filler body a specific weight such as e.g. barium sulphate, but cheaper and lighter filler body materials can be resorted to. There is now the possibility of using a plastic material which is doped with zinc, as well as other heavy filler materials such as e.g. clay, glass, liquid fillers, chalk, powdered fillers and the like.
Particularly preferred here is a filling with polyamide-zinc, zinc in powdered form being introduced into a liquid polyamide plastic melt in a ratio of preferably 80% to the polyamide composition (measured gravimetrically). Other mixture ratios are possible as well.
Such a filler body can also be made by plastic injection moulding, has a very stable shape and is therefore suited to receiving an inlay portion between itself, without it being necessary also to use special further measures for the strength of the filler body.
In addition to forming the material of the filler body from a polyamide zinc compound, a polybutylene terephthalate zinc compound can be used as well. This last-mentioned compound PBTP in combination with the above-mentioned zinc powder also leads to the result that the central filler body consisting of the upper portion and the lower portion can be made as a stable plastic portion which receives the inlay portion inside it.
The filler body is in particular designed in two portions, for it consists of a filler body upper portion and a filler body lower portion belonging thereto, the two portions being joined and/or meshed together in form-locking relationship. Form-locking meshing of this kind can be achieved for example by interlocking mortise and tenon joints, by adhesive joints, by friction-locking joints such as e.g. xe2x80x9cbayonetxe2x80x9d, or press stud joints or joints by injection moulding technology with a plastic composition.
Here the nature and construction of the inlay portion are not important. The inlay portion can be for example a transponder which consists of a single-layer or multi-layer coil in whose interior is arranged a microprocessor which ensures transmitting and receiving operation. The inlay portion can also be an ordinary filler portion or be completely omitted, providing a passive chip.
Naturally the material of the filler body should not shield the inlay portion electrically if the inlay portion is designed as a transponder, as transmitting and receiving operation would suffer from this.
If on the other hand such a transponder is dispensed with, metal shielding is not important.
For the design of the decorative lid films and decorative laminates (star cup and star lid), films that can be injection-moulded and graphically designed (e.g. printed on) are used, with relative freedom in the film thickness. In this case film thicknesses within the range of for example 100-300 xcexc can be used.
The surface of the film should preferably be satin-finished and/or have a high gloss.
Naturally these films can be printed on by all known printing methods. Safety printing methods can be employed too, and additional pigments, colour mixtures and the like can be used.
The invention is however aimed at the general structure of the plastic body, so that the design of the films themselves is not important.
Inter alia, the following further advantages arise with the present invention:
attainable weight easily +/xe2x88x9210 grammes, with choice of materials polypropylene with 50% glass; polyamide and polyoxymethylene with the addition of barium sulphate in the region of 70% would be possible too.
very exact colours and colour fidelity possible, with very strong shades of colour
good abrasion resistance, first and foremost of the edges (white fracture) and of the graphic design
very large advertising area of the film
good chemicals resistance
good light-fastness
good stacking capacity
good prevention or difficulty of forgery
no need for metal fillers, therefore use of transponders as inlay portion quite easily possible
pleasant sound, when used as a games token
pleasant haptics: the xe2x80x9chandlexe2x80x9d and the surface or feel is high-quality and sympathetic
variable dimensions: 36 and 40 mm in EU standard, also with 34, 38, 43, 45 mm diameter.
The subject of the present invention results not only from the subjects of the individual patent claims, but also from the combination of the individual patent claims with each other. All the particulars and characteristics disclosed in the documents including the abstract, particularly the three-dimensional construction shown in the drawings, are claimed as essential to the invention as far as they are novel individually or in combination compared with the state of the art.